With the G1, Merosi designed the first vehicle under the Alfa Romeo label in a new design for the automobile manufacturer. Merosi had developed the car at home during the dispute over Nicola Romeo’s terms of purchase. The G1 was an “update” of the pre-war models 24 HP and 20/30 ES. The luxury model with the longer, stiffer chassis was meant to compete with Rolls-Royce. A 4-stroke in-line engine with 6330 cc and six cylinders, each with two valves, produced 294 Nm and delivered 70 hp on the road.
The roadster with its petrol engine and unstabilised axles thus reached a remarkable maximum speed of 138 km/h. Alfa Romeo used the car in motorsport and won the Coppa de Garda in his class with the G1. Rising petrol prices and the post-war turmoil prevented the success of this beautiful model. Altogether the Italian produced only 52 vehicles, the planned successor, the G2 in a modified version, was never built due to the commercial failure. In Italy there were hardly any buyers for the G1.50 model went to Australia. An importer in New Zealand has the last remaining G1, which is the oldest remaining vehicle from Alfa Romeo.